2. Something which in form or action resembles the common
hammer; as:
(a) That part of a clock which strikes upon the bell to
indicate the hour.
(b) The padded mallet of a piano, which strikes the wires,
to produce the tones.
(c) (Anat.) The malleus. See under {Ear}.
(d) (Gun.) That part of a gunlock which strikes the
percussion cap, or firing pin; the cock; formerly,
however, a piece of steel covering the pan of a
flintlock musket and struck by the flint of the cock
to ignite the priming.
(e) Also, a person or thing that smites or shatters; as,
St. Augustine was the hammer of heresies.
[1913 Webster]

He met the stern legionaries [of Rome] who had
been the ``massive iron hammers'' of the whole
earth. --J. H.
Newman.
[1913 Webster]

3. (Athletics) A spherical weight attached to a flexible
handle and hurled from a mark or ring. The weight of head
and handle is usually not less than 16 pounds.
[Webster 1913 Suppl.]

{Hammer shell} (Zo["o]l.), any species of {Malleus}, a genus
of marine bivalve shells, allied to the pearl oysters,
having the wings narrow and elongated, so as to give them
a hammer-shaped outline; -- called also {hammer oyster}.

Forging — This article is about the metalworking process. For specific hot forging hearth, see forge. For the act of counterfeiting, see forgery. Hot metal ingot being loaded into a hammer forge Forging is a manufacturing process involving the shaping of… … Wikipedia